Rauka S=•2•[0;π]∫4•(1-cosφ)dφ= =4•[0;π]∫(1-2cosφ+cosφ)dφ= =4•(φ-2sinφ) [0;π]+2•[0;π]∫(1+cos2φ)dφ= =4π+(2φ+sin2φ)[0;π]=4π+2π=6π (ед. площади) .